I worked part time in a gun shop right after I got off active duty. We had people come in the night before deer season ,they would buy a gun, scope ammo , and ask me to bore sight it. That would be close enough for anything under 400 yards. Hate to say it, but I heard that more than once. Had a younger guy come in once for ammo. I asked him what he needed and he said. 7mm. I ask him which 7mm. He got jacked and said to get someone over to help him that knew something about guns. I said I could name about 10 different 7mm cartridges off the top of my head and we carried about 6 or seven of them. He said "f you" im not buying from liars and dumba##/$! and he stormed out. Hope he had the day he deserved at another shop!